It's a Sig SRD762Ti in 7.62. My friend tried to attach it and said that the mount goes over the threads and only catches about 2-3 of them. He said he thinks that it needs to be "downturned" adding more threads. You can see the threads don't start until well into the mount. If the threads started right on the edge of the inside of the mount it would be fine. Watching a video from Sig you can see John Hollister I think screw his mount onto a bolt action rifle at least 4-6 full turns.

I don't think there is another mount specifically for .300 Blackout since it's .30 cal which is the same as 7.62, correct? Maybe I need a different mount.

He said that he would like to see 4-6 full turns onto the threads which is 1/2" inch while he's currently only seeing less than 2 full turns which is only 1/8" of an inch right now. He said it's solid but it could potentially come loose and cause issues.

Anyone have a problem with a Sig QD mount not attaching to a Ruger American Ranch Rifle in .300 BO?

Apparently there are different adapters for different rifles. The suppressor comes with the adapter that fits the Sig line of weapons, no surprise there. I wish they would have put this on their website, that different rifles require different adapters. The new adapter I received definitely has a lot more threads in it and they start far earlier making the threads start far closer to the end of the adapter. I'm happy that I didn't have to do anything drastic like downturn the barrel or buy a custom adapter.

I know that Sig has been knocked in the past for having some horrible customer service but I've got to say that I was treated great. Their employee went out of his way to take care of me.